.tab{
  width: 100%;
  height: 152rpx;
  display: flex;
  justify-content: space-around;
  align-items: center;
  background: url(http://doc.bufanui.com/uploads/a411524237/images/m_ab6bcc12252d7f508bc0c193a94ac6cd_r.png) no-repeat;
  background-size: 100%;
  .tab-item{
    transform: translateY(30rpx);
    image{
      width: 64rpx;
      height: 64rpx;
    }
    &:nth-child(3){
    transform: translateY(0rpx);
    }
    &:nth-child(3) image{
      width: 116rpx;
      height: 116rpx;
    }
  }
}